Manufacture of furane



July 19A, 1927.

w. c. wlLsoN MANUFACTURE 0F FURANE Filed Nov. 28. 1924` Patented July 19, 1927.

1,636,030 PATENT OFFICE.

WILLIAM COUB'INEY WILSON, OF CHICAGO, ILLINOIS, ASSIGNOR T0 THE QUAKER j OATS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

MANUFACTUBE F FURANE.

Application filled November 28, 1924. Serial No. 752,530.

This invention relates to improved processes and apparatus for manufacturing furalic substances and particularly furane.

Furane has heretofore been obtained only as a laboratory product from furoic acid by a decomposition orbreaking down of. the acid into furane and other substances when subjected for a long period of time to hlgh temperaturesand pressures within a sealed tube. By this method, even with careful manipulation, it has been fpossible to obtain only'small quantities o furane merely as an experimental result and at great expense.

This invention, accordingly, has for one of its objects the provision of a process for rapidly manufacturing fui-ane in large quantities from fur'oic acid. A further o ject of this invention is/to provide a process by which the furane may-be removed from the region of the furoic acid substantially as soonv as formed, whereby possible condi-l tions inhibiting the progress of the reaction are obviated and whereby the reaction is permitted to proceed to a conclusion by which a much larger percentage of the acid is converted to furane than has been heretofore possible.

A further object ot this invention comprises the provision of a relatively simple process and apparatus for the commercial production of fur-ane at a cost such that this chemical may be made available for use for many purposes where its. cost has heretofore been prohibitive.

Another object of this invention is to provide a method for the simultaneous produc tion of'furane and furoic acid in extremely pure form. l,

Further objects and advantages of the invention here disclosed will appear from the following specification and appended claims i taken in conliectionwith the accompanying drawing, which illustrates one embodiment of the apparatus in invention may be carried out.

Furoic acid, even when only slightly `heated at substantially atmospheric pressure, is subject to sublimation. This fact would lead to the belief that the furoic acid would largely or wholly become sublimed before being heated suiiiciently to break down the acid into furane and carbon dioxide in the absence of pressures higher than atmospheric.

nhich the process of my At the same time a portion of the furoic acid- .will vaporize but this result is not seriously objectionable in carrying out my process, since in accordance with my invention the vapors substantially aboutv 400 the furoic acid will condense and thus become separated from the other gases produced.

In accordance with my process, after the furoic acid is removed, the gases may be. passed through a solution of a suitable chemical such as caustic soda, for the absorption of the carbon dioxide. rane vapors may then be condensed form and collected in a receiver.

The sublimed furoic acid which is collected in the condensing chamber by the above process is very much purer than the furoic acid which may be used as the initial raw material for the process and it is possible to utilize initially a crude form of furoic acid and by suitable temperature and other control obtain furane and refined furoic acid 1n varying proportions, that is, this process may be operated so as to produce a major quantity of furane and a lesser quantity of sublimed furoic acid, or if desired it may be operated so as to produce a major quantity of sublimed furoic acid and a lesser quantity of furane.

It has been my observation that the percentage of furoic acid that is decomposed during the operation of my process depends to a largeextent upon the length of time during which heated particles ofthe material remain in. their heated condition. As an illustration, I have practiced my process by using a still in which to heat the furoic acid, snch still being provided with a substantially horizontal or downwardlyv turned outlet cori- .duit extending fromA a point very closely adto liquid The fujacent the surface of the furoic acid in the still. With the apparatus thus arranUed, the gases and vapor freely and very rapidly flow from the still as formed and accordingly are not subjected to the temperature of the still for any appreciable period of time. Under such conditions, the major quantity of sublimed Auroic acid and a lesser quantity of furane may be produced.

In the accompanying drawing, an apparatus is illustrated suitable for commercially carrying out the process ot' my invention. Although not limited to such use, this apparatus is particularly desirable for the production of a major quantity of urane by my process.` Briefly, the apparatus may comprise a still 1, or vessel for receiving the uroic acid, a condensing chamber 2, a carbon dioxide absorber 3, a condenser 4, and a receiving tank 5.

The still 1 may comprise a tank or vessel of suiiicient size for receiving a considerable quantity of the uroic acid crystals. As illustrated, the vessel may be partly or wholly surrounded by a steam jacket 6, provided with inlets and outlets as at 7 and 8,v respectively. The vessel 1 may be provided with a suitable opening 9, through which the uroic acid may be introduced, and a cover 10 for such opening.

The vapors emitted from the still may pass through a passageway 11 to the condensing chamber 2. The condensing chamber is preferably provided with a cooling jacket 12 for maintaining the receiver at a temperature in the neighborhood of 40o C. Suitable inlets and outlets 13 and 14, respectively, are provided for the cooling fluid. The condensing chamber, as illustrated, may embody a tortuous passageway formed by a series of balies as at 15 and 16. The sublimed furoic acid will gather upon the cold walls and batie plates of the condensing chamber, whereas the remaining gases will pass on into the adjacent carbon dioxide absorber 3.

The carbon dioxide absorber', as illustrated, may comprise a receptacle 17 provided with a series of partitions as at 18, the lower edges of which are extended into a quantity of a solution such as caustic soda suitable for the absorption of carbon dioxide. As indicated by the arrows in the drawing, the gases entering may be caused to bubble through the caustic solution at the lower edges successively of the partitions 18. The caustic solution may be maintained at a suitable ten'iperature by means of a steam coil as illustrated at 19. Suitable inlets and outlets as at 20 and 21, respectively, may be provided for renewing the caustic solution.

The remaining gas comprising Jfurane vapor is allowed to pass `through a conduit 22 into the condenser 4, which may be of any suitable and well-knewn type or as illustratthe carbon dioxide absorber' ed. From the condenser 4 the liquid furane may be conducted through a conduit 23 into the receiving vessel 5. The vessel 5, if desired, may be provided with an air vent as at .24 in order that the process may be carried out at substantially atmospheric pressure.

With apparatus of the above described type, I have found that two hundred parts of commercial furoic acid of 95-96% purity will yield in the neighborhood of seventyone parts of furane and twelve parts of sublimed furoic acid when heated to temperatures in the neighborhood of 200 C. or about one hour. Thus it will be seen that this invention provides a process for producing urane in commercial quantities and without the use of costly or complicated apparatus. The furane made available by this process is also of a high degree oi' purity.

Although the above description and the accompanying drawing merely disclose in detail one specific process and a single form ot apparatus for carrying out the process embodying my invention, I desire that only such limitations be imposed upon m invention as are set forth in the appende claims. Certain features ot the process may be altered within the scope of my invention in its broader aspects. For example, the furane vapor may be separated from the other gases formed by purifying processes other than that disclosed herein.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A process for the production of furane which comprises heating uroie acid atsubstantially atmospheric pressure.

2. A process for the production of urane which comprises heating uroic acid at substantially atmospheric pressure and continuously removing the urane from the region of the acid.

3. The Rrocess of manufacturing fura'ne which comprises breaking down furoic acid to urane by means ot' heat at substantially atmospheric pressure and separating urane from the resulting reaction products.

4. The process of manufacturing urane which comprises heating furoic acid at substantially atmospheric pressure to a temperature in the neighborhood of 200o C. or more and separating furane vapor from the resulting reaction products.

5. A chemical process which comprises heating furoic acid in a vessel to a temperature sufficient to cause decomposition thereof into furane and carbon dioxide, and allowing the gases formed to continuously pass from the vessel.

6. A chemical process which comprises heating furoic acid in a vessel to a temperature suiiicicnt to cause decomposition there-l of into furane and carbon dioxide, and allowing the gases formed to continuously :,eaaoso 3 pass from the vessel through a carbon dioxpassing the gasesr through a condensi 1de absorbing material. p l chamber whereby sublimed furoic acid 1s 7. The process ofrmanufacturing furane deposited in the chamber, and also assing w which comprises first heating furoic acid in the gases through avbath of a solution for a vessel at substantially atmospheric presthe absor tion of carbon dioxide therefrom, sure to a temperature suflcient to cause deand final y condensing the furane varor. composition of a portion thereof into furane, 11. The process of manufacturing urane passlng the gases formed through a condens which com rises first heating furoic acid in ing chamber wherebg7 sublime furoic acid`A an enclose vessel at substantially atmos-y is de osited in the c mber, and also' treatpheric pressure to a temperature in the V ingt e gases with a chemical for-the absorpneighborhood of 200 C. or more, allowing ,allowing the gases forme tion of carbon dioxide therefrom. the gases formed to continuously pass from v 8. The proce of manufacturing furane the vessel, then passing the gases through a V6.0' I which comprises first heating furoic acid in condensin chamber whereby sublimed fua vessel at substantiall atmospheric resroic acid 1s deposited in the chamber, then sureto a temperature 1n the neighbor ood paing the remaining ases through abath of 200 C. or more, allowing the gases of caustic solution for t e absorption of carforme'd to lcontinuously assfrom the vessel, bon dioxide therefrom, Aand finally condens- 65 and through a bath of) a solution for the ing the furane vapor. absorptionof carbon dioxide therefrom, and 12. A vchemical rocess which comprises finally condensingA the furane vapor. 'heating furoic aci to a temperature sui- 9. The process of manufacturing furane cient to causesublimation and decompoaiy which comprises first treating furoic acid in tion of a portion thereof, and passi the 00 a vessel to cause furane va or to be evolved, ases formed through a condensing amd) to continuously r whereb vsubstantially pure furoic acid pass `from the vessel, passing the gases is deposi within said chamber.

through a condensing chamber whereby 13. A process of obtaining furane and subsublimed furoic acid is deposited in the stantially pure furoic acid which comprises 65 chamber,and also assing the gases through heating furoic acid in a vessel to a temperaa bath of a material for the absor tion of ture vsuilcient to cause decomposition of a' 4carbon dioxide'therefrom, and fina y conportion ereof and' allowing the densin the furane vapor. formed tocontinuously ass from the vessel 10. he process of manufacturing furane. through a condensing c amber where puri- 70 which comprises first heating furoic acid in fied furoic acid is deposited. a vessel toa temperature in the neighbor- Inwitness whereof, I have hereunto subhood of 200 C. or more, allowing the gases scribed m name.

formed to continuously pass from the vessel, WIL IAM COURTNEY WILSON. 

